Digital Teaching Aid 
No. 1 In a workshop two machines are driven by an electric motor
Power consumption: 
motor A = 1 KW 

motor B = 2 KW 
For a new machine of which its motor C receives the power of 4 KW, the maximum main power of Pmax = 4 KW is sufficient only if the two other machines (A and B) are not switched on. Design a circuit which supplies a warning signal Q if a power higher than 4 KW is taken from the main power system by the three machines.
 Truth table
 Karnaugh map
 Logic circuit
No. 2 For a display of the figures 16, in the well known spot configuration of a game die, design the code conversion circuit. At the input the figures are binary coded.
T, U, V, W, X, Y, Z are output variables (LED's)
 Truth table
 Karnaugh map
 Logic circuit
No. 3 Design a JK Flip Flop with NAND and AND gates.
 Logic circuit
 Truth table
No. 4 Design a D Flip Flop. Use only NAND gates.
 Logic circuit
 Truth table